1. Field of the Invention
The present invention relates to methods and apparatus for incubating and hatching eggs and more particularly to such methods and apparatus in which eggs are placed in an environment in which factors such as temperature and relative humidity are monitored and controlled.
2. Description of the Related Art
Egg incubators in which humidity and temperature are controlled to optimize the number of hatched eggs are known in the art. For example, U.S. Pat. No. 2,026,801 to Ross discloses a humidity and temperature control for incubation. The Ross incubator uses a first coil for conducting steam and a second coil for conducting cold water to regulate temperature in the incubator. In Ross, steam is conducted in the steam coil to bring the incubator temperature to approximately 100.degree.. When temperature arises above 100.degree., cold water is circulated to cool the incubator.
The Ross device suffers from several drawbacks. First, it is inefficient to simultaneously circulate steam and cold water. In addition, the coils for circulating hot and cold fluids in Ross are substantially horizontal thereby creating a possibility of air entrapment in the lines. Such coils are difficult to clean in place due to their construction and they are not easy to remove for remote cleaning and disinfecting.
U.S. Pat. No. 3,923,006 to Dugan et al. discloses a method and apparatus for incubating eggs. Although the Dugan et al. incubator incorporates heating, cooling and humidifying apparatus on a cart which may be rolled into and out of an incubator, it utilizes an electrical heating element and includes structure which is difficult to thoroughly clean and disinfect.
Cleaning and disinfecting incubators and all of the equipment therein is crucial to prevent growth of microorganisms which damage the incubating eggs and reduce the yield and quality of hatchlings.
A number of prior art devices for holding eggs in an incubator are known. Although some incorporate parallel dividers for separating rows of eggs, such as U.S. Pat. No. 1,573,038 to Branington and U.S. Pat. No. 324,274 to Rosebrook, the prior art devices do not provide a means for varying the space between the dividers to accommodate different egg sizes, e.g., chicken eggs versus turkey eggs.
U.S. Pat. No. 1,345,483 to Ewry discloses an egg tray having a removable divider; however, only one size divider is disclosed. Prior art egg trays tend to be designed for either incubating or hatching. An incubating tray is generally relatively short in height and is constructed to receive a number of eggs in close proximity to one another. A hatching tray, on the other hand, has higher sides and is designed for greater spacing between eggs to accommodate chicks after they are hatched. Usually, eggs are transferred from an incubating tray to a hatching tray prior to completion of egg incubation.
It is a general object of the present invention to provide a method and apparatus for incubating and hatching eggs which overcomes the above-enumerated prior art problems.
It is a more specific object of the present invention to provide such a method and apparatus which utilizes circulating fluids to heat or cool an incubator.
It is another specific object of the present invention to provide such a method and apparatus which diminishes the chance for air to be trapped in the fluid circulation system.
It is another specific object of the present invention to provide such a method and apparatus which is easy to clean and disinfect.
It is another object of the present invention to provide such a method and apparatus which easily accommodates eggs of different sizes.
It is another object of the present invention to provide such a method and apparatus which is transferless, i.e., one in which there is no need for transferring eggs between an incubating tray and a hatching tray.